Apparatus for folding of envelope blanks requiring varying numbers of folding operations

ABSTRACT

A first cylinder is provided on its periphery with circumferentially spaced alternately arranged folding grippers and blades. A second and a third cylinder each cooperate with the first cylinder and define therewith one and another folding station. The second and third cylinders are respectively provided with alternately arranged folding grippers and blades, and with blades above, on their respective circumference, and these second and third cylinders are of identical dimensions and are interchangeable. Drive means is provided for rotating the cylinders about respective parallel axes. A pressing belt presses an envelope blank against the periphery of the first cylinder, and a removing arrangement removes folded blanks from a terminal one of the folding stations.

United States Patent 11 1 1111 3,837,266

Honsel Sept. 24, 19741 [54] APPARATUS FOR FOLDING OF ENVELOPE 3,758,102 9/1973 Munn et al. 270/69 BLANKS REQUIRING VARYING NUMBERS FOREIGN PATENTS OR APPLICATIONS OF FOLDING OPERATIONS 743,434 ll/l943 Germany [76] Inventor: Karl-Heinz Honsel, Heidelberger 679,676 8/1939 Germany 93/61 R Weg l5, Bielefeld, Germany Prima ExaminerRo Lake [22] Flled' May 1973 Assista nt Examiner-filai nes F. Coan [21] Appl. No.: 360,163 Attorney, Agent, or Firm-Michael S. Striker Related US. Application Data [63] Continuation-in-part of Ser. No. 228,398, Feb. 22, [57] ABSTRACT 1972, p 3,793,92 A first cylinder is provided on its periphery with circumferentially spaced alternately arranged folding [30] F r i A li ti P i it D t grippers and blades. A second and a third cylinder Feb. 23, 1971 Germany 2108484 eaeh cooperate with the first eyhhder and define May 20, 1972 Germany 2224810 therewith one and another folding Staheh- The Second and third cylinders are respectively provided with al- 52 US. Cl 93/62, 93/13, 93/84 R e arranged feeding gripper? blades and [51] Int. Cl B3lb 1/56 Wlth blades above on respecuve clrcumference, [58] Field of Search 93/62, 61 R, 84 R, 8 R, and these second and third cylinders are of identical 93/13 dimensions and are interchangeable. Drive means is provided for rotating the cylinders about respective [56] References Cited parallel axes. A pressing belt presses an envelope UNITED STATES PATENTS blank against the periphery of the first cylinder, and a removing arrangement removes folded blanks from a 2,903,946 9/1959 l-lonsel 93/13 terminal one of the folding stations 3,557,666 l/l97l Stemmler..... 3,668,982 6/1972 Stemmler..... 4 Claims, 1 Drawing Figure APPARATUS FOR FOLDING OF ENVELOPE BLANKS REQUIRING VARYTNG NUMBERS OF FOLDING OPERATIONS BACKGROUND OF THE INVENTION The present invention is a continuation-in-part of my copending application Ser. No. 228,398, filed on Feb. 22, 1972, now US. Pat. No. 3,793,926, under the title APPARATUS FOR FOLDING OF ENVELOPE BLANKS.

It is known to provide envelope blanks which in the unfolded (i.e. planar) state have two flaps which must be folded over and are provided on certain marginal portions with adhesive, frequently with self-adhesive strips or the like. Envelope blanks of this type can be readily folded and sealed, without requiring moistening, but only if the surfaces to be contacted and sealed to one another are both coated with the self-adhesive material. For this reason such folding envelopes have a second closure flap which is located beneath the actual outer closure flap so that the surface portions which are provided with the self-adhesive material will not come in contact with one another while the envelope is being stored prior to the time of use.

During such storage it is necessary to protect the selfadhesive material against light which tends to disadvantageously affect, if not destroy, the adhesive capability of this material. For this reason the blanks must be so folded in the making of the envelope that the actual upper closure flap is in a position which it will later assume when the envelope is to be sealed, whereas the lower closure flap must be so folded that its surface provided with the self-adhesive material faces the surface of the envelope. Apparatus is known which folds such blanks in that it first provides for a preliminary bending of the blank material along the fold lines, whereupon the blank is supplied to a further station of the apparatus which uses essentially two cooperating rollers and a deflecting device for the leading portion of the blank which is to be folded over. However, this apparatus requires that the blank to be folded must be advanced with a sliding movement until it is engaged at the leading edge of the portion to be folded, by the aforementioned rollers, because the leading portion of the blank must be folded back and must therefore remain freely movable. It has been observed in such operations that the development of a fold or crinkle will frequently result, and of course this leads to a significant amount of wastage in the production of envelopes from such blanks on the aforementioned machines. These problems are overcome with the apparatus disclosed in my aforementioned copending application which comprises a plurality of folding stations corresponding in number to the plurality of folding operations to be performed on a blank, including an initial station and a terminal station. A plurality of rotary folding grippers and folding blades are provided on each of the folding stations, and drive means is provided for rotating the grippers and blades of the initial folding station so as to effect folding of a blank in one direction, and the grippers and blades of all other folding stations in such a manner as to effect folding of the blank in an opposite direction to the one direction. Removing means removes folded blanks from the terminal folding station.

The apparatus uses two cooperating cylinders, of which each is alternately provided on its circumference with folding blades and folding grippers, and which together form two folding stations. One of these cylinders constitutes with a further cylinder which is provided with folding blades spaced about its periphery, a third succeeding folding station. An advancing pressing band is provided which presses the blanks against the periphery of one of the cylinders and which advances at a higher angular speed or velocity than the cooperating cylinder, thereby eliminating the danger that the small closure flap of the blank might open up again after the folding operation, and thus making it possible to carry out all folding operations exclusively with rotary grippers and blades which permit reliable folding of the blank without forming crinkles in the blank material and which further can operate with a very high production speed.

However, my aforementioned improved apparatus, can be used only for folding of envelope blanks having the previously mentioned two closure flaps, namely and upper and a lower closure flap. Evidently, there are instances when it is desirable to be able to fold envelope blanks having only a single flap. This, however, cannot be carried out with the aforementioned apparatus.

SUMMARY OF THE INVENTION It is, accordingly, an object of the present invention to provide an improvement in my aforementioned apparatus which will permit the same to be used for folding of envelope blanks which have either one or two closure flaps.

More particularly it is an object of the present invention to so improve my aforementioned apparatus that it can be selectively used to fold envelope blanks having one or two closure flaps.

In keeping with the above objects, and others which will become apparent hereafter, one feature of the invention resides in an apparatus for folding of envelope blanks requiring varying numbers of folding operations. The apparatus comprises a first cylinder provided on its periphery with circumferentially spaced alternately arranged folding grippers and blades. A second cylinder and a third cylinder are provided, each cooperating with the first cylinder and defining therewith one and another folding station. One of these second and third cylinders is also provided with alternately arranged folding grippers and blades on its circumference, and the other of the second and third cylinders is provided with folding blades on its circumference. These second and third cylinders are of identical dimensions and interchangeable. Drive means is provided for rotating the cylinders about respective parallel axes, and a pressing belt presses an envelope blank against the periphery of the first cylinder. Removing means removes folded blanks from a terminal one of the folding stations.

With this construction, in which the second and third cylinders are of identical dimensions and are interchangeable with one another, it is a simple matter to remove the second and third cylinders from their respective locations and to interchange them, depending upon whether the apparatus is to operate on envelope blanks requiring folding operations for producing of two flaps, or only for producing a single flap. This means that in a very simple manner, in particular without having to carry out any substantial structural changes, the apparatus according to the present invention can be rapidly converted from folding of envelope blanks requiring a number of folding operations requisite for producing two flaps to folding of blanks requiring a number of folding operations for a single flap, and vice versa. The envelope blanks having a single flap will, of course, not utilize self-adhesive material but instead of the type wherein the adhesive on the flap must be moistened for activation. It is not necessary to keep special cylinders in stock or to carry out complicated modifications.

The novel features which are considered as characteristic for the invention are set forth in particular in the appended claims. The invention itself, however, both as to its construction and its method of operation, together with additional objects and advantages thereof, will be best understood from the following description of specific embodiments when read in connection with the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS:

The single FIGURE is a diagrammatic sideelevational view of an apparatus embodying the present invention.

DESCRIPTION OF THE PREFERRED EMBODIMENTS:

The apparatus according to the present invention as shown by way of example in the drawing has been illustrated in diagrammatic form with all those components having been omitted which are not necessary for an understanding of the invention. Concerning those components, which are conventional, reference may be had to my aforementioned copending application which is to that extent incorporated herein.

Returning to the FIGURE it will be seen that reference numeral a identifies a cylinder which cooperates with two additional cylinders lla and 12a. The arrangement is such that during a single revolution of the cylinder 10a three envelope blanks are folded, and that during such single revolution of the cylinder 10a each of the cylinders 11a and 12a will perform three complete revolutions of its own.

Distributed uniformly about the circumference of the cylinder 10a there are provided three folding blades 13a, 13a and 13a" which cooperate with the folding gripper 14a of the cylinder 11a. Equally evenly distributed about the circumference of the cylinder 10a are folding grippers 15a, 15a and 15a" which cooperate with the folding blade 16a of the cylinder Ila. The cylinders 10a and Ila together define a first folding station which is used when blanks are to be folded to produce envelopes having two flaps, that is when the fold ing station is to carry out two folding operations.

A third folding operation is required for envelope blanks having two flaps. This third folding operation is carried out in a second folding station which is defined by the cylinder 10a in cooperation with a cylinder 12a. The latter has a folding blade 19a which cooperates with folding grippers 18a, 18a and 18a" which are evenly distributed about the circumference of the cylinder 10 2. In addition, the cylinder 12a is provided with a suction device 20.

Subsequent to the second folding station there is provided a gripper drum or a gripper cylinder 22b having a gripper device 220 which engages the folded blanks and transfers them to a diagrammatically illustrated conveyor 26a to be carried away thereby.

Intermediate the cylinders 11a and 12a there is provided a pressing band 17a which is associated with the cylinder 10a and which advances at a greater angular speed than the angular speed of the cylinder 10a. The pressing band 17a will of course in actual fact be much closer to the circumference of the cylinder 10a than is illustrated.

The cylinders 11a and 12a are of identical dimensions and interchangeable in accordance with the present invention. They are mounted so that they can be readily removed and equally readily installed, so that there is no difficulty in removing the cylinder Ila and replacing it with the cylinder 12a after the latter itself has been removed from its mounting.

In the illustrated embodiment the machine is set up to process envelope blanks which are to be converted into envelopes having two flaps. Reference character A designates that when the machine is to be converted to a different operation the cylinder 12a can be removed and kept in storage until it is needed again, whereas reference character B indicates that the cylinder 11a can be removed and installed in place of the cylinder 12a. Once these operations are carried out, the folding blade 19a of the cylinder 12a cooperates with the folding grippers 15a, 15a and 15a of the cylinder 10a to produce a single folding action, that is the single folding action which is required to produce ordinary envelopes having a single flap the adhesive of which must be wetted to be activated, rather than protected as in the case of the self-adhesive material of double-flap envelopes. It is of course assumed that when the machine has been transformed in this manner it will operate on envelope blanks whose side flaps have already been folded in and which are provided with the necessary adhesives since the folding of the side flaps and the application of the adhesives do not form a part of the present invention.

It will be understood that each of the elements described above, or two or more together, may also find a useful application in other types of constructions differing from the types described above.

While the invention has been illustrated and described as embodied in an apparatus for folding of envelope blanks, it is not intended to be limited to the details shown, since various modifications and structural changes may be made without departing in any way from the spirit of the present invention.

Without further analysis, the foregoing will so fully reveal the gist of the present invention that others can by applying current knowledge readily adapt it for various applications without omitting features that, from the standpoint of prior art fairly constitute essential characteristics of the generic or specific aspects of this invention and, therefore, such adaptations should and are intended to be comprehended within the meaning and range of equivalence of the following claims.

What is claimed as new and desired to be protected by Letters Patent is set forth in the appended claims:

1. Apparatus for folding of envelope blanks requiring varying numbers of folding operations, comprising a first cylinder provided on its periphery with circumferentially spaced alternately arranged folding grippers and blades; a second cylinder and a third cylinder each cooperating with said first cylinder and defining therewith one and another folding station, one of said see 0nd and third cylinders also being provided with alternately arranged folding grippers and blades on its circumference, and the other of said second and third cylinders being provided with folding blades on its circuma speed which is greater than the angular speed of said first cylinder.

3. Apparatus as defined in claim 1, wherein said removing means comprises a rotating additional cylinder provided on its periphery with a gripper device for removing said folded blanks.

4. Apparatus as defined in claim 3, wherein said removing means further comprises a conveyor arranged to receive said folded blanks from said additional cylin- 

1. Apparatus for folding of envelope blanks requiring varying numbers of folding operations, comprising a first cylinder provided on its periphery with circumferentially spaced alternately arranged folding grippers and blades; a second cylinder and a third cylinder each cooperating with said first cylinder and defining therewith one and another folding station, one of said second and third cylinders also being provided with alternately arranged folding grippers and blades on its circumference, and the other of said second and third cylinders being provided with folding blades on its circumference, said second and third cylinders being of identical dimensions and interchangeable; drive means for rotating said cylinders about respective parallel axes; a pressing belt for pressing an envelope blank against the periphery of said first cylinder; said number of folding stations corresponding to the number of folding operations to be performed on said blank; and removing means for removing folded blanks from a terminal one of said folding stations.
 2. Apparatus as defined in claim 1, wherein said pressing belt advances relative to said first cylinder at a speed which is greater than the angular speed of said first cylinder.
 3. Apparatus as defined in claim 1, wherein said remOving means comprises a rotating additional cylinder provided on its periphery with a gripper device for removing said folded blanks.
 4. Apparatus as defined in claim 3, wherein said removing means further comprises a conveyor arranged to receive said folded blanks from said additional cylinder. 